JP2021104382A - Method of manufacturing article - Google Patents

Abstract

To provide a method of manufacturing, via an additive manufacturing process, an article which, when mounted later on a holding device of a machine tool, controls the position of itself to a known position and orientation.SOLUTION: The method comprises performing a second manufacturing process to transform an article 20 into a second state, where the second manufacturing process is a subtractive process comprising (i) mounting, via mounting features 18 formed during an additive manufacturing process, the article on a holding device of a machine for operating the article, with support structures or at least remnants of the support structures remaining on the article, and (ii) in a state where the article is mounted on the holding device, processing at least one feature 14 on a surface of the article on which the support structures were provided, so as to remove material on at least the one feature provided by the support structures.SELECTED DRAWING: Figure 4b

Description

The present invention relates to a method for producing an article, eg, an article comprising at least one dental restoration.

Rapid manufacturing techniques are becoming more widely used for the production of various parts. In particular, the technique of manufacturing parts for each layer has become more and more known and used in the industry of manufacturing custom-made parts. Selective laser sintering is one such rapid manufacturing technique that allows products to be made layer by layer from powdered materials such as powdered metals. For example, a powder material layer can be applied to the base of a laser sintering machine and then the laser is controlled to sinter or melt selected parts of the powder material to form a first layer of parts. .. Another powder layer is then applied to the top and the laser is again controlled to sinter or melt the other layer of the part. This process is repeated until the entire part is formed. The formed parts are then removed from the powder table. Such techniques are well known and are described, for example, in Patent Document 1 and Patent Document 2.

Compared to more traditional techniques such as milling parts from billets or blanks, such techniques help enable rapid manufacturing, facilitate the manufacture of complex parts, and minimize material waste. Can be. As a result, the manufacture of parts using such technology is becoming more desirable. In fact, it is known to use such techniques to form dental restorations, especially dental frameworks, which are typically complex custom parts.

However, the products produced by such techniques sometimes require additional work to change the surface finish of the part and / or the accuracy of some features that cannot be achieved by rapid manufacturing techniques alone. ..

Patent Document 3 discloses a technique in which a plurality of dental prostheses are formed in a frame by a rapid prototyping method while the frame is held in a finishing machine tool. Patent Document 4 discloses a grip fixing and connector structure for gripping a semi-finished part in a finishing machine tool, and the semi-finished part is formed by selective laser sintering. Patent Document 5 discloses a drill template formed by rapid prototyping using a reference point, which reference point is used to position the drill template on a milling machine for subsequent processing. Patent Document 6 published after the priority date of the present application discloses a dental bridge intermediate structure including a superstructure, which superstructure comprises a connecting piece, which connecting piece to an incisor. A connecting means for connecting the dental bridge intermediate structure is provided.

European Patent No. 1021997 European Patent No. 14642298 European Patent No. 194688 International Publication No. 2011/124474 Pamphlet European Patent No. 2238941 International Publication No. 2012/064257 Pamphlet International Publication No. 2013/167905 Pamphlet

H. J. J. Bradick, "Mechanical Design of Laboratory Apparatus", Chapman & Hall, London, 1960, pages 11-30

The present application is a method of manufacturing an article by an additive manufacturing process, wherein the article comprises at least one (eg, set) mounting feature, the article being later mounted within a holding device of a machine tool. In some cases, it illustrates a method of controlling the position of the article to a known position and orientation.

According to the first aspect of the present invention, there is a method of manufacturing an article, which is a step of acquiring an article formed in an initial state by utilizing an additive manufacturing process, wherein the article is at least one. A step of acquiring a mounting feature (eg, of a set) and a step of transforming the article into a second state by performing a second manufacturing process, wherein the article is at least one (eg, of the set). A step of mounting the article in a holding device of a machine that works on the article via a mounting feature, such as in a linear 3 degree of freedom and a rotation of 3 degrees of freedom in the operating space of the machine. The position and orientation of the holding device is constrained (and, eg, recognized and defined by it) by interacting with the at least one (eg, set) mounting feature of the holding device. And a method is provided that includes a step of deforming the article, including a step of processing at least one feature.

Therefore, the additive manufacturing process is utilized to form the bulk of the article, and the second manufacturing process can be utilized to finish some side or features of the article. By providing at least one mounting feature that defines the position of the article in the operating space of the machine, the need to explore the article to determine the position of the article prior to work on the article is eliminated. Can be done. The position and orientation of the article can be reliably recognized when the article is mounted within the machine by the at least one mounting feature. In particular, it can constrain the lateral position in the three orthogonal degrees of freedom and the rotational orientation around the three orthogonal rotation axes in a known manner. Therefore, the at least one mounting feature may be described as a positioned mounting feature. This is because the step of processing the at least one feature portion in the article requires scrutiny of the position of the article, for example, without exploring the article to find the position of the article. It can mean that it can be performed immediately, without the time-consuming position and / or orientation specific action.

There can be two main causes for the error in the position of the at least one feature to be machined. One source of error is the uncertainty of the position of the at least one feature that will be machined relative to the at least one (eg, set) mounting feature (and thus to the holding device of the machine). Can be sex. This error can depend on the accuracy of the additive manufacturing process. Thus, such errors may vary depending on the accuracy of the additive manufacturing process, but are typically recognized and can be defined for the process utilized. Another source of error can be determined by the position reproducibility of the article having the holding device of the machine (eg, the configuration of at least one (eg, set) mounting feature and the corresponding feature on the holding device. ) Can be. Preferably, the at least one (eg, set) mounting feature is i) the position of the article (eg, the position of the article) of uncertainty about the position of the portion (eg, at least one feature that will be machined). The ratio to reproducibility is, for example, 50: 1 or less, more preferably 10: 1 or less, particularly preferably 5: 1 or less, for example 4: 1 or less. It is configured to be 1: 2 or less. As is clear, the positional uncertainty of the part and the position reproducibility of the article can be measured as the position tolerance diameter.

Thus, preferably, the method, as well as the at least one (eg, set) mounting feature of the article and the holding device, is the operating space of the machine when the article is mounted within the holding device. The position of the at least one feature to be machined within is more preferably 50 μm (micron), for example within a predetermined required tolerance and, for example, within a position tolerance diameter of 100 μm (micron). ) Is configured to be recognized within the position tolerance diameter.

The at least one (eg, set) mounting feature has a linear position along all three mutually perpendicular axes in the operating space of the machine and a rotational orientation around those axes. Can be configured to be recognized and defined by interacting with the at least one (eg, set) mounting feature.

For example, the at least one (eg, set) mounting feature can be a kinematic mounting feature. As is apparent, and as described, for example, in Non-Patent Document 1, kinematic design involves using a minimum number of constraints to constrain the degree of freedom of motion of the body or features. Especially with avoiding excessive constraints. This means that the highly reproducible positioning of the article with respect to the holding device is ensured and the article is located on the holding device in a predictable and recognized manner. Thus, such a kinematic mounting feature can engage the corresponding kinematic mounting feature on the holding device of a tool (eg, a machine tool) for working on the article.

Due to the high load incurred during machining, the use of kinematic mounting features to hold articles for machining has previously been unthinkable. Therefore, there was a technical prejudice against the use of kinematic attachment features for this purpose.

The article can also include a coarse alignment feature that constrains the coarse orientation in which the user can place the article on the holding device. In particular, preferably, they are configured such that the article can be placed in only one orientation on the holding device. Such features may be realized by the at least one (eg, set) mounting feature. Optionally, they are realized as features separate from the at least one (eg, set) mounting feature. Preferably, such coarsely oriented features are realized by engagement of the at least one (eg, set) mounting feature on the article with the corresponding feature on the holding device, the position of the article and Does not interfere with orientation control.

The article is made by the additive manufacturing process according to a computer model such as a CAD model of the article.

Therefore, the second manufacturing process can include a step of determining the position of the feature portion of the article using the data regarding the position of the feature portion. Such data can be derived from the computer model. Therefore, the method may include the step of receiving data regarding the location of at least some features of the article.

The article may be made layer by layer by the additive manufacturing process. The article can be made by a laser solidification process such as a laser sintering process or a laser melting process, also known as selective laser sintering or selective laser melting. Optionally, the article can be made by a laser cladding process, a Fused Deposition Modeling (FDM) process, or an electron beam melting process. The method can include the step of forming the article by the additive process.

The second manufacturing process can be a subtractive process. Therefore, the step of processing at least one first feature can include the step of removing the material from the article. For example, the machine can be a machine tool, in which the second manufacturing process includes the step of machining at least a portion of the article, for example by milling.

The article can be processed from multiple sides. For example, the article can be processed from both sides. This can be achieved by mounting the article so that it can be accessed on multiple sides by the processing machine. This can be achieved by rotating the article during the second manufacturing process. Therefore, the second manufacturing process may include a step of processing the first side portion of the article and then a step of rotating the article to perform the work on another side portion of the article. It is possible. More specifically, the second manufacturing process includes a step of processing the first side portion of the article and then a step of inverting the article and performing the work on the opposite side portion of the article. It can be included. This can include, for example, a step of machining the first side portion of the article and then a step of rotating the article to machine the opposite side portion of the article. The article can be rotated by the holding device. That is, the holding device can have a rotation axis.

During the second manufacturing process, the at least one first feature may be completely formed. Optionally, the at least one first feature can be at least partially preformed in the article by the additive manufacturing process. Therefore, the step of processing the at least one first feature portion can include a step of finishing the at least one first feature portion. This can include the step of removing the material on the at least one first feature. Therefore, the at least one first feature can include excess material that is removed during the second manufacturing process. Thus, if the method comprises forming the article by the additive process, the step can include adding excess material to at least the at least one first feature. be. Such excess material can ultimately exceed the desired amount for the finished product.

The article can include at least one dental restoration. The article can comprise a dental restoration supported by at least one implant. The dental restoration can be an abutment. The dental restoration can be a single dental restoration, for example an implant-supported abutment or crown. Other materials may be added to the dental restoration to finish the restoration. For example, porcelain or crowns can be added to achieve a finish that is more aesthetically similar to natural teeth.

The second manufacturing process can include machining a portion of the dental restoration that will be joined to another object, such as another member in the patient's oral cavity. This can be important to ensure a good fit. Ensuring a good fit can be important for a number of reasons, for example structurally to reduce the likelihood of failure of the restoration. Ensuring good fit can also be important to reduce or avoid gaps where bacteria can inhabit. For example, the method will be joined to a tooth prepared to receive the restoration, commonly known as a "prep" in the patient's oral cavity or an implant in the patient's jaw. It is possible to include the process of machining. The dental restoration can include at least one portion for joining to at least one member in the patient's oral cavity, for example at least one implant member, and the second manufacturing process is at least said. Includes the process of machining one part.

The article can include a plurality of products joined together. As is clear, the products can later be separated from each other. Therefore, multiple products can be formed and processed at the same time. Since they are joined together, they can be transported together and attached together in the machine for carrying out the second manufacturing process.

The article can include at least one product and at least one member on which the at least one (eg, set) mounting feature is provided. Therefore, the at least one (eg, set) mounting feature may be provided separately from the product. As will be appreciated, the at least one member can be later separated from the product after all processing requiring the member. The member can be a holding member (eg, a clamp member) capable of holding (eg, clamping) the article and defining and maintaining its position during the second manufacturing process. The at least one member may include a central hub around which the at least one product is located.

The plurality of products may be joined together by the at least one member.

The plurality of products can include a plurality of dental restorations. For example, the plurality of products can include a plurality of dental abutments.

If the article is supported by a scaffold on the lower side of the article during the additive manufacturing process, the at least one feature that will be processed in the article is located on the same side as the scaffold. Can be done.

The at least one feature may be processed into the article on the surface of the article provided with the scaffold during the second manufacturing process.

According to another aspect of the present invention, there is a method of manufacturing an article, which is a step of obtaining an article in an initial state formed by utilizing an additive manufacturing process, wherein the article is attached to at least one. A step of acquiring a feature portion and a step of transforming the article into a second state by carrying out a second manufacturing process, wherein the article is subjected to the at least one mounting feature section. The article includes a step of mounting the article in a holding device of the machine performing the work and a step of deforming the article, including a step of processing at least one feature portion in the article, when the article is in the additive manufacturing process. A method is provided in which the at least one feature is supported by a scaffold on the lower side of the article and is machined on the article on the same side as the scaffold during the second manufacturing process.

The position and orientation of the article in three linear and three rotational degrees of freedom in the operating space of the machine can be recognized by interacting the holding device with the at least one mounting feature. Can be done.

The at least one mounting feature may include a kinematic mounting feature that engages the corresponding kinematic mounting feature on the holding device of the machine tool.

The at least one feature may be processed into the article on the surface of the article provided with the scaffold during the second manufacturing process.

According to another aspect of the present invention, there is a method of manufacturing a dental restoration, i) a step of forming an initial state dental restoration body by an additive process, wherein the dental restoration body is at least. A step of forming a mounting portion having one set of position feature portions, and ii) a step of mounting the dental restoration body in an initial state in a machine tool by at least one set of position feature portions of the mounting portion. , Iii) The dental restore body is made into a second by machining the dental restore body from both the first side portion and the second side portion that substantially face each other. A method is provided that includes a step of transforming into a state.

Therefore, the method of the present invention efficiently forms an accurate dental restoration by utilizing different manufacturing techniques at different stages.

The use of additive processes can be advantageous over machining the entire dental restoration body from a solid blank, as it requires significantly less material and may require less time. It also allows the formation of geometries that are not possible with the machining process alone.

By providing the position feature portion, the need for exploration to confirm the position of the dental restoration main body in the machine tool can be eliminated. The position feature can ensure that the position of the dental restore body is recognized when it is mounted within the machine tool.

Step iii) is a step of machining the dental restoration body from the first side portion of the dental restoration body, a step of reorienting the initial state dental restoration body, and then the initial state dental restoration. It is possible to include a step of machining the dental restoration main body from the second side portion of the main body.

The at least one set of positional features can include at least one set of kinematic mounting features.

The dental restoration body is joined to an implant in the patient's jaw that is present on one of the first side and the second side of the dental restoration (the dental restoration in the patient's jaw). It is possible to have at least one joint for (to place things).

It can be important that the at least one joint (the area of the dental restoration body facing the implant in the patient's jaw) has a very precise finish. Without such a high precision finish, the fit between the implant and the joint can be inadequate, which is because the dental restoration is in the patient's jaw. It can lead to inadequate fixation.

Therefore, in the initial state of the dental restoration body, the at least one joint can be formed with an excess of the required material. The method can further include the step of machining the at least one joint to remove at least a portion of the excess material.

A plurality of joints may be provided spaced apart along the restoration body. This is especially true if the dental restoration is an implant bridge. When the plurality of joints are not accurately formed, for example, when the distance between the joints is different from the distance between the corresponding implants in the patient's jaw, the dental restoration body may It has been found that it can be distorted when fixed in place. This strain can lead to stresses within the restoration body, which in turn can lead to undesired stresses on the implant. The stress applied at the attachment can cause discomfort to the wearer and can lead to the dental restoration body becoming loose or even failing.

Therefore, the method can include the step of machining at least one of the plurality of joints to remove excess material, thereby manipulating the relative positions of the plurality of joints with respect to each other. Is.

The at least one joint may be provided on the second side of the dental restoration body.

The at least one junction can be an implant junction for joining to an implant immobilized in the patient's jaw.

The initial state of the dental restoration body can be provided with at least one hole for receiving a fixture for fixing the dental restoration body to the implant in the patient's jaw. As is clear, the surface to which the restoration body is abutted by the head of the fixture may require a high level of smoothness to ensure a stable fit. Therefore, the method can include the step of finally forming the at least one hole by machining the at least one hole.

The step of machining the at least one hole can be performed from the first side of the dental restoration body.

The additive process can include a selective laser melting / sintering process.

The dental restoration can be an abutment. The dental restoration can be an implant-supported abutment.

The dental restore body can form the final outer shape of the dental restore. Optionally, the dental restore body can be a body or "framework" on which an outer structure can be formed to provide the final outer shape of the dental restore. Therefore, the method can include the step of adding an outer structure to the body. The outer structure can include a porcelain layer.

According to another aspect of the present invention, there is a method of manufacturing an article, which is a step of forming an article in an initial state by utilizing an additive manufacturing process, wherein the article moves, for example, at least one set. A method is provided that includes a step of forming, comprising at least one (eg, a set) mounting feature, such as a scientific mounting feature (ie, formed by the additive manufacturing process). The method can include mounting the article within the holding device of the machine via the kinematic mounting features of the set.

According to a further aspect of the invention, there is provided an article made by an additive manufacturing process comprising at least one (eg, set) mounting feature, eg, at least one set of kinematic mounting features. NS.

According to a further aspect of the present invention, an article produced by an additive manufacturing process comprising at least one feature that requires processing in the second manufacturing process, wherein the article is the additive manufacturing process. An article is provided in which the article is sometimes supported by a scaffold on the lower side of the article and the at least one feature portion to be processed during the second manufacturing process is located on the same side as the scaffold. .. The scaffold, or at least the rest thereof, may remain on the article.

The article may include at least one dental restoration.

The at least one feature may include at least a portion of the dental restoration that will be joined to another member in the patient's oral cavity. The second manufacturing process may be a process in which at least a part thereof is machined.

The at least one feature may include at least one portion for joining to at least one implant member.

According to a further aspect of the present invention, it is a method of manufacturing an article, a step of acquiring an article in an initial state, and a series of steps of acquiring the article including at least one mounting feature. A step of transforming the article into different states in each of the series of manufacturing processes by carrying out two or more manufacturing processes, the at least one mounting feature for each of the series of manufacturing processes. In the step of attaching the article into a holding device of a machine that works on the article during the manufacturing process, the article in three linear and three rotational degrees of freedom in the operating space of the machine. The position and orientation of the attachment is recognized and defined by interacting the holding device with the at least one attachment feature, including the attachment step and the process of processing the article. Methods are provided, including.

The at least one mounting feature may include a kinematic mounting feature that engages the corresponding kinematic mounting feature on the holding device of the machine.

The article in the initial state having the at least one mounting feature may be formed utilizing an additive manufacturing process.

According to a further aspect of the invention, a product or article made by a method as described herein is provided.

In addition, the present application describes a method for producing an abutment supported by a dental implant, which comprises a step of producing an abutment containing a portion for joining the implant member layer by layer from a powder material by a laser sintering process. .. Such a method can include processing at least a portion of the abutment after the laser sintering process.

The process of processing can include removing the material from the abutment, for example via machining. The method can include processing a portion to be joined to the implant member. The process of processing can include, after the laser sintering process, a step of mounting the abutment in a device for holding the abutment during the process of processing. The laser sintering process can include the step of making a mounting portion connected to the abutment for mounting the abutment within the device for holding the abutment during the processing process. Is. Preferably, the abutment and the attachment are currently formed or still formed when the abutment is mounted within the device for holding the abutment during the process of machining. Not on the axis of the hole in the abutment (which can receive an implant screw or a screwdriver to secure the implant screw), and optionally, for example, on the axis of the portion for joining to the implant member. In contrast, the longitudinal axis of the abutment, which may be, for example, parallel or even coincident, is configured to be parallel to a tool, such as a cutting tool, for machining the abutment. The laser sintering process can include the step of making a plurality of abutments connected to the same mounting portion. At least two, and preferably all, of the plurality of abutments are in the same direction for joining to the implant member, for example so that their longitudinal axes are parallel to each other. It can be oriented as it is oriented.

Hereinafter, the present invention will be described as a preferred embodiment of the present invention with reference to the accompanying drawings.

It is the schematic of the selective laser sintering machine for forming an article. It is the schematic cross-sectional view of the implant abutment attached to the support implant. It is a schematic bottom view of the article provided with a plurality of abutments connected to a central hub in the initial state. It is a schematic bottom view of the article provided with a plurality of abutments connected to a central hub in the initial state. It is a schematic top view of the article shown in FIG. It is a schematic top view of the article shown in FIG. It is a flow chart which shows the method by this invention. FIG. 3 is a schematic cross-sectional side view of the laser-sintered articles of FIGS. 3 and 4 still mounted on the fabrication plate at the time of manufacture. FIG. 3 is a schematic cross-sectional side view of the laser-sintered articles of FIGS. 3 and 4 clamped using a kinematic attachment in a machine tool. FIG. 6 is a schematic view of an implant joint being machined into the bottom surface of a dental restoration. FIG. 6 is a schematic view of an article flipped upside down by a clamp member in preparation for machining a hole in an abutment.

The following description presents an example of how the present invention can be used to produce implant-supported abutments. As is clear, the implant-supported abutment is of a particular type, when used, is fixed to a dental implant pre-implanted in the patient's jaw to hold the dental restoration in the patient's oral cavity. It is a dental restoration. Typically, implant-supported abutments are used to replace a single tooth. The abutment supported by the implant is typically made from a metal-based structure so that the porcelain, bridge, or crown achieves the desired finish shape and appearance of the abutment before fitting it. Will be added to this abutment.

Of course, the present invention is not limited to the manufacture of implant-supported abutments, but can also be utilized in the manufacture of other types of dental restorations, such as bridges or crowns. However, the present invention is generally not limited to dental restorations. Rather, the invention can be utilized in the manufacture of a wide variety of different types of products, such as other types of medical implants, aerospace components, and jewelry.

As is clear, the abutment supported by the implant needs to be precisely made to ensure that the abutment fits comfortably and permanently in the patient's oral cavity. It is known to make dental abutments from blanks or "billets" of sufficient volume so that the entire abutment can be machined as a single piece using a machine tool such as a CNC milling machine. Obviously, in the case of implant-supported abutments, the blank can be a solid metal piece, such as a titanium or cobalt-chromium alloy. Other materials, such as zirconia, can be used, but in this case a metal link member is often required between the zirconia body and the implant. In either case, such milling / machining techniques result in the formation of high precision abutments, which are time consuming, expensive and costly.

The embodiments described according to the present invention utilize an additive process to create an initial form of the abutment. In this case, an additional machining process is utilized to further machine at least the selective area of the abutment. The use of additive processes can be advantageous over machining the entire dental restoration body from a solid blank, as it requires significantly less material and may require less time.

FIG. 1 shows a typical configuration of a production chamber 210 for a selective laser sintering / melting machine. The fabrication chamber 210 defines a space 220 above the descendable fabrication platform 230. The fabrication chamber 210 includes a powder distribution and coating device 240 for spraying the powder 250 on the surface of the fabrication platform 230. An article to be manufactured by the window 255 in the upper wall of the chamber 210, which directs the laser beam 260 to radiate the powdered material onto the fabrication surface 270 and selectively sinters / melts the powder. It is possible to form 20 layers. The laser and descendable platform 230 can be controlled by a control device 280, such as a PC, that has a program that defines the process for forming the article 20. This program can control the laser sintering process based on the CAD data of the parts to be formed. In particular, the CAD data can be divided into a plurality of layers, each of which corresponds to a layer that will be formed by the laser sintering process.

FIG. 2 shows how the completed dental restoration, which in this case is the implant abutment 12, can be anchored to the implant 4 in the patient's mandible 5 in its final state. Adjacent teeth are not shown in this drawing for simplicity. As shown, the addition of the outer layer of the porcelain 3 to the abutment 12 realizes the final outer shape of the dental restore 2. FIG. 2 shows the implant / abutment junction 6, which is the region where the abutment 12 and the implant 4 engage with each other. This is the surface portion of the abutment 12 that should be finished with high precision. As shown, the abutment 12 comprises a hole 8 formed therein in which the implant screw 10 can be placed. The hole 8 includes an upper section 13 and a lower section 15. The lower section 15 has a smaller radius than the upper section 13, especially the head of the screw 10 used to secure the abutment 12 to the implant 4. As shown, when the screw 10 is screwed through the hole 8 into the implant 4, it firmly secures the hole 8 and thus the abutment 12 to the implant 4.

FIG. 2 also shows the appearance profile region 7 between i) the implant junction 6 and ii) portion 9 of the abutment 12 (often referred to as the coronal region 9) to which the porcelain / crown is added. .. This appearance profile region can also be described as the region between the implant junction 6 and the abutment edge 11. As is clear, this rim is usually understood as the edge around the abutment where the porcelain or crown is intended to be placed. Therefore, this area of the metal surface of the abutment is exposed and is in direct contact with the patient's gingiva 11, the protective periodontal tissue. This area is commonly referred to in the dental field as the "appearance profile" or "transitional protective periodontal area". It can be important that this appearance profile region 7 is smooth in order to avoid irritation or protective periodontal tissue and to prevent bacterial colonization. This area can be smoothed by a suitable polishing technique.

3a and 3b and 4a and 4b show a bottom view and a top view of an article 20 made from powdered cobalt-chromium by a laser sintering process, respectively. The article 20 comprises a plurality of individual abutments 12, each mounted on a common location hub 22 by a connecting bar 21. As shown, the bottom surface of each abutment 12 comprises a circular disc / boss-like excess material protrusion 14 into which the implant junction 6 of the abutment 12 is also formed by machining. Further, these figures further show that on one side of the location hub 22, there are three v-shaped groove feature 18s that define the kinematic attachment. As described below, these three v-groove features 18 are placed in a known position and orientation within the space of the machine tool device by the machine tool clamp 25 (discussed in more detail below). Is used for accurate placement. Further, as shown in the figure, the location hub 22 further includes two coarsely oriented holes 17 extending over the entire length of the location hub 22. As described below, these holes 17 can be used to ensure the correct coarse orientation of the article 20 within the machine tool clamp 25. As shown, all abutments 12 are oriented so that their longitudinal axes 32 are parallel to each other. Further (and as shown in FIG. 8a), the abutment and mounting section have an abutment longitudinal axis 32 in the longitudinal direction of the cutting tool 31 when the article 20 is mounted within the clamp 25 during later machining. It is configured to be parallel to the axis.

FIG. 5 is a flow chart showing a method for producing an abutment 12 supported by an implant according to an embodiment of the present invention. Each of the illustrated steps will be described with reference to FIGS. 6-8.

In the first step 110, the abutment 12 in its initial state is made utilizing a rapid manufacturing process, which in this example is a selective laser sintering process. As is apparent, the selective laser sintering process iteratively adds a powder material layer to article 20 by using a selective laser sintering machine such as those schematically shown in FIG. 1 and described above. It involves doing. A high intensity laser is focused on the area of the powder material that matches the appropriate shape of the article 20 for the appropriate layer to bind the powder. The surface to be sintered is then lowered so that the laser can focus at the same height the next time the powder material is applied, but scans through the powder around an appropriate path. Will be done. In the embodiments described, the abutment 12 is one of articles 20 comprising a plurality of abutments 12 (eight abutments in this example) also connected to a hub 22 formed by a laser sintering process. Formed as an abutment.

FIG. 6 shows a cross-sectional view of an article 20 made by selective laser sintering but still located on the making plate 24. The article 20 is mounted on a support structure 23, which is a web of sintered material having a lower density than the article, but supports the article and is of its own weight and internal thermal stress. It is strong enough to prevent distortion under both. The support structure 23 is also referred to herein as a scaffold or support web. As is clear, although not shown, the fabrication plate 24 may be much larger than the article 20 to be produced, which may allow multiple articles to be produced at the same time. Further, as can be seen from FIG. 6, when the article 20 is supported by the scaffold 23 on the lower side of the article 20 during the additive manufacturing process, the mounting feature 18 is on a different side of the article 20 without the scaffold 23. (That is, on the upper side of the article 20).

The second step 120 follows the completion of the selective laser sintering process, removing the fabrication plate 24 and the article 20 from the selective laser sintering apparatus and preparing them for machining. including. Preparation may include various optional steps, such as placing the article 20 in an industrial oven along with a support web 23 and a fabrication plate 24 so that a stress relief heat treatment cycle can be performed. The article 20 is then removed from the fabrication plate 24 by cutting the support structure 23, and any remaining portion of the structure 23 is removed with pliers and a polishing rotary tool. Article 20 can then be grit blasted to make the entire surface smoother. Occasionally (for example, depending on the use of a polishing tool before blasting), even after grit blasting, the side of the article 20 that was connected to the support structure 23 and the rest of the support structure 23 on the article 20. It may still be significantly coarser than the opposite side due to remaining in. As shown, the appearance profile region 7 of the abutment 12 and the excess material 14 from which the implant joint will be machined are present on the surface of the article 20 provided with the support structure 23.

As described above, the machining of the abutment 12 in the initial state can be a multi-step process because the abutment 12 may require machining of the feature portion from the opposite direction.

As shown in FIG. 7, subsequent step 130 includes mounting the article 20 in its initial state on a mounting structure, which in this case is a clamp 25, in a machine tool such as a computer numerically controlled (CNC) milling machine. .. FIG. 7 shows a schematic view of the article 20 in the initial state in which the clamp 25 is clamped in place by engaging the location hub 22. The clamp 25 comprises a base 27, which has three hemispherical protrusions 28 arranged on its upper surface 30 (only two of them are shown in FIG. 7). The protrusion 28 is arranged so that it can engage the kinematic feature 18 on the location hub 22, thereby facilitating the kinematic attachment of the article 20 to the clamp 25. Further, the clamp 25 includes an upper clamp member 26, and the upper clamp member 26 urges the location hub 22 to the base 27 by engaging with the location hub 22, thereby firmly holding the article 20 in place. And hold. In this case, the upper clamp member is a screw 26, which extends through a hole 29 in the location hub 22 so that its thread (not shown) is a base member. By engaging and tightening the corresponding thread in 27, the head of the screw 26 pushes the kinematic feature 18 of the location hub 22 into the kinematic feature 28 of the base 27. The article 20 is clamped so that the surface to be machined faces upward.

The excess material 14 provided in step 140 and on each abutment 12 is then machined by a milling tool 31 of a computer numerically controlled (CNC) machine tool device to implant 4 It forms an implant-bonded structure 6 that can engage the corresponding features above. The kinematic features constrain the position and orientation of the article 20 and thus the abutment 12 within the machine tool's operating space in all three linear and all three rotational degrees of freedom. Therefore, this machining process can be performed without the need to explore the article 20 to determine its location. That is, the position of the abutment 12 can be estimated from the perception of the position to be located with respect to the location hub 22. In this example, each article 20 is made according to the Standard Model so that each excess material portion 14 can be assumed to be located in a predetermined position. That is, it is recognized that the article 20 includes eight abutments 12 and that the excess material portion 14 of each abutment 12 is located at a predetermined position with respect to the location hub 22. In particular, in this embodiment, the method and especially the kinematic features are aware of the position of the abutment 12 and, more specifically, the position of the excess material portion 14 within a position tolerance diameter of 100 μm (micron). Is set. Therefore, the accuracy of the laser sintering process is such that the uncertainty of the position of each abutment 12 with respect to the kinematic mounting feature 18 is within the position tolerance diameter of 80 μm (micron), and the position reproducibility of the assembly is 8 μm (). It will be within the position tolerance diameter of (micron). Therefore, the ratio of i) the uncertainty of the position of each abutment 12 to the kinematic mounting feature to the reproducibility of ii) the kinematic mounting feature is 10: 1.

By precisely defining the location of the location hub 22 by the kinematic mounting feature 18 on the hub 22 and the kinematic mounting feature 28 on the base 27, the position of the excess material portion is also precisely defined and recognized. And can be estimated by the machine tool device performing the milling operation. As is clear, this does not necessarily have to be the case, for example, the location of some features, such as the excess material portion 14, of the article used to make the article, for example during the laser sintering process. It can be determined from data suggesting the position of the feature portion, such as being determined from a CAD model or the like.

In the embodiments described above, the base 27 of the clamp is connected to a rotating unit 33 capable of rotating the clamp 25 about a rotation axis A, whereby the article 20 can be turned upside down in the machine tool device. The calibration routine has already been performed so that it is known how the rotation of the clamp 25 about the axis A affects the position of the article 20. Therefore, in the next step 150, the article 20 is inverted as shown by FIG. 8b, and then the hole 8 is machined to finish, so that the shoulder of the screw head and the mating surface in the hole 8 are paired. Accompanied by ensuring close contact with 9. Since the clamp 25 has already been calibrated, it is possible to accurately finish / form the hole 8 with respect to the implant joint structure 6. This is important to ensure the alignment of the hole with the implant and to avoid excessive bending force on the screw connecting the abutment to the implant. In the embodiments described above, the drilling 8 is partially formed during the additive manufacturing process and then precisely finished during this machining process. However, as is clear, this does not necessarily have to be the case, for example, the drilling is completely formed by this machining process (ie, the drilling structure is initially entirely by the additive manufacturing process. It is possible (not formed).

The final step 160 includes removing article 20 from the machine tool. The location hub 22 and the connector 21 are removed from the abutment 12, and the rest of the connector 21 is manually polished. The layer of porcelain 3 or crown structure can then be added to the abutment 12 to form an implant abutment before it is fixed to the implant 4 in the patient's jaw.

In one embodiment of the present invention, the article 20 needs to be machined on a plurality of different machines at different time points and is held in each machine so that the positions of the parts of the article 20 are recognized. Is particularly useful for multi-step processing of article 20 in which By providing at least one mounting feature on the article 20 that defines the position of the article 20 in the machine operating space (in each operating space of each different machine in multi-step machining), the article 20 is provided before the work on the article 20 is performed. The need to explore the article 20 at each stage to determine the position can be eliminated. At least one mounting feature can ensure that the position and orientation of the article 20 is recognized when it is mounted within each machine of multi-step machining. Such an advantage can be realized regardless of how at least one mounting feature is formed, i.e., the at least one mounting feature need not be due to an additive manufacturing process. It will be appreciated that it can be formed by a subtractive process such as milling or a combination thereof. For example, the various machining steps may include an inspection step, one or more machining steps, and a polishing step, as well as one or more additional machining steps. For an example of the polishing stage, refer to Patent Document 7. In Patent Document 7, the article is not required to be held in an accurate position and orientation within the electropolishing machine and therefore does not have a positioned mounting feature, but the electropolishing machine of Patent Document 7 does. It will be readily appreciated that it can be easily adapted to receive articles with positioned mounting features. Further, Patent Document 7 describes a machining step after the electrolytic polishing step in which an article is clamped in a machine tool and a machining operation such as machining / milling of an abutment is performed on the article. It is disclosed.

Referring again to FIG. 6, the excess material 14 from which the implant joint will be machined is on the surface of the article 20 on which the support structure 23 was provided, i.e., on the same side as the support structure 23. In particular, it is noticed again. This is somewhat counter-intuitive. This is because, usually during the additive fabrication process, the article 20 requires the support structure 23 to be positioned away from the surface, which is considered to be very important, and a smooth or precise finish. This is because they are placed so that they are placed on a surface that does not.

For example, in the case of a dental framework, a very important part is the implant junction and the upper surface of the framework is less important. Because it will be covered with a layer of porcelain anyway, and it will be the porcelain that gives the restoration its final appearance. In practice, the surface roughness caused by the rest of the support structure 23 remaining on the article 20 can be seen as an advantage as it acts as a key for holding the porcelain layer firmly.

However, the opposite of what is considered normal is to place the support structure 23 on the same side as a very important joint or any other feature that will be machined in the second manufacturing step. Applicants understand that there are significant advantages in applying this practice. In a two-step manufacturing process where a very important joint will be machined in the second stage anyway, the presence of a support structure on the very important joint is a problem. It doesn't become. Also, by performing additive manufacturing in this orientation, manual finishing or polishing is not required on the top surface (eg of the implant bridge), and in this regard, prefabricated articles on the top surface. It is often required to be fitted, and if it already had a polish-removed support on its surface, this surface could thereby maintain sufficient accuracy. , Will be low.

In order to realize this advantage, the mounting feature 18 is of a type (kinematic, etc.) that precisely defines the position and orientation of the article in the machine operating space by joining the mounting feature 18 to the holding device. It will be understood that it does not have to be a thing. Thus, at least one mounting feature may include a kinematic mounting feature that engages the corresponding kinematic mounting feature on the holding device of the machine tool, but this is not required. If such preformed initial kinematic mounting features 18 are not provided, and if the location of the features to be machined in article 20 is important (as in this case). Alternatively, an alternative process (eg, exploration work) may be utilized to determine the position of the article 20 within the operating space of the machine tool.

Claims (15)

A method of manufacturing goods
(A) A step of performing an additive manufacturing process (110) to form an article (20) in an initial state, wherein the article (20) includes a mounting feature portion (18) and the additive manufacturing process (20). During 110), the process supported by the support structure (23) and
(B) The second manufacturing process includes a step of performing a second manufacturing process to transform the article (20) into a second state.
(I) The article (18) is attached to the holding device (25) of the machine for operating the article (20) via the mounting feature (18) formed during the additive manufacturing process (110). 20) with the step (130) of attaching the support structure (23) or at least the rest of the support structure remaining in the article (20).
(Ii) At least one feature on the surface of the article (20) provided with the support structure (23) with the article (20) so attached to the holding device (25). Subtraction including the step (140) of processing the portions (6, 14), the step of removing the material on at least one feature portion (6, 14) provided by the support structure (23). A method characterized by being a process. The article (20) is supported on the fabrication plate (24) by the support structure (23) during the additive manufacturing process (110), the method being performed prior to the attachment step (i). The method according to claim 1, further comprising a step of removing the article (20) from the production plate (24). The attachment feature (18) of the article (20) engages with the corresponding kinematic attachment feature (28) of the holding device (25) of the machine in the attachment step (i). The method according to claim 1 or 2, wherein the attachment feature portion (18) is provided. A method of manufacturing goods
(A) A step of executing an additive manufacturing process (110) to form an article (20) in an initial state, wherein the article includes a mounting feature (18).
(B) Each of the second manufacturing processes in the series includes a step of executing a series of two or more second manufacturing processes.
(I) A machine holding device for manipulating the article (20) during the second manufacturing process via the mounting feature (18) formed during the additive manufacturing process (110). In the step (130) of attaching the article (20) to (25),
(Ii) With the step (140) of processing at least one feature portion (6, 14) on the article (20) with the article (20) so attached to the holding device (25). , Including
The attachment feature (18) of the article (20) engages with the corresponding kinematic attachment feature (28) of the holding device (25) of the machine in the attachment step (i). A method characterized by being a target mounting feature portion (18). At least one processing step (ii) of the second manufacturing process in the series includes a step of inspecting, machining, or polishing at least one feature (6, 14) on the article (20). The method according to claim 4, which is characterized. In the processing step (ii), the position and orientation of the article (20) with three linear and three rotational degrees of freedom in the operating space of the machine is determined by the kinematic attachment feature of the article (20). 18) Any of claims 3-5, characterized in that it is constrained by the interaction of the holding device (25) with the kinematic attachment feature (28), eg, known and defined. The method described in Crab. In the processing step (ii), the position and orientation of the article (20) in the linear 3 degrees of freedom and the rotational 3 degrees of freedom in the operating space of the machine are (A) the overall known in the mounting step (i). Constrained by the interaction of (B) the kinematic attachment feature (18) of the article (20) with the kinematic attachment feature (28) of the holding device (25). For example, the method according to claim 6, characterized in that it is known and specified. The additive manufacturing process (110) additionally forms the article (20), including the mounting feature (18), from the material according to the computer model of the article (20), resulting in the mounting feature. Compared to (18), at least one feature portion (6, 14) on the article (20) includes a step that can be derived from the computer model of the at least one feature portion (6, 14). The position is determined in the processing step (ii) using data derived from a computer model regarding the position of at least one feature (6, 14) with respect to the mounting feature (18) of the article (20). The method according to any one of claims 1 to 7. The method according to any one of claims 1 to 8, wherein the processing step (ii) includes a step of machining at least one feature portion (6, 14) of the article (20). The article (20) is provided with at least one product (12) and a mounting feature (18) of the article (20), which is later separated from the at least one product (12) (160) at least one. A claim comprising one member (22), wherein the at least one member (22) optionally includes a central hub around which the at least one product (12) is arranged. The method according to any one of 1 to 9. The article (20) is supported by the support structure (23) on its underside during the additive manufacturing process (110) and / or of the article (20). The method according to any one of claims 1 to 10, wherein the mounting feature portion (18) is provided on the surface of the article (20) without the support structure (23). The article (20) is formed layer by layer by the additive manufacturing process (110) and / or the additive manufacturing process (110) comprises a laser consolidation process and / or the additive manufacturing process (110). The method according to any one of claims 1 to 11, wherein the process comprises a laser sintering or laser melting process. The method according to any one of claims 1 to 12, wherein the at least one feature portion (6, 14) comprises an excess of material that is removed during the second manufacturing process. The method according to any one of claims 1 to 13, wherein the mounting feature portion (18) is formed on one side of the article (20). The at least one feature portion (6, 14) is said to have the article (ii) in the processing step (ii) without prior exploration of the article (20) to determine its position in the operating space of the machine. 20) The method according to any one of claims 1 to 14, characterized in that it is processed above.

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